I was recently sent a Raspberry Pi 4B computer, disassembled, with little introduction or fanfare. I have heard much about the miniature hobby computer over the past decade, but hadn’t actually used one or seen one up close until now. I put it together, and observed that it didn’t POST on its own. Being a tiny motherboard, it has no BIOS at all, and is completely dependent on the installed operating system for hardware detection and testing. I downloaded and installed a Debian image made for Raspberry Pi using their imager you could download from their website.
It boasts a quad-core ARM Processor (Revision 3). It is not your average Intel processor. All of the largest chips on the motherboard each take up no more than 1 square cm, and the heat sinks are so small that they attach like little aluminum decals to their processors. It comes with 4GB RAM installed, and a place for a Micro-SD for the operating system and limited storage. It can support up to two 4K HD monitors at 60 frames per second, each connected with micro-HDMI connectors. It has connectors for legacy Type-A USB2 and USB3 devices. I am using the two USB2 connectors for the mouse and keyboard; and the other two for “anything else”. There is a third Type-C USB3.1 connector which is used for power. The power switch itself is on the same cable as for the power supply. You can also hook up a standard Ethernet cable for connecting to a network. If you don’t have ethernet, the Pi boasts a WiFi receiver. The motherboard goes inside a plastic system box about the size of a small pack of cigarettes.
On the motherboard are pinouts which resemble the ones used for the old parallel ATA connectors from decades ago. After learning how to send power to which pin through a comnputer program, the possibilities of operating small electrical devices (lights, speakers, an arduino device, what else …?) expand greatly.
The installation had a few hitches, since it appears I cracked the first two micro SD cards either on the supplied USB adaptor, or on the micro-SD mount provided underneath the motherboard. I went and purchased a third, a 32GB Sandisk Ultra (I could have gone as low as 4GB, but this was the smallest sold by Staples). I installed the OS using their installer again, and this one booted. Since I was at home, I didn’t have access to my supplied monitor, keyboard and mouse, so I just reconnected existing devices at home, and was rewarded by a rather nice X-Windows display.
The Pi is bluetooth-enabled, but I hadn’t tried it yet. I did plug in a wireless adapter for a Logitech keyboard/mousepad combo (the K400 Plus), and it worked instantly.
Now, since I was given this computer as a teaching tool for students, I made the default account password-protected, and created a new account named “student” with fewer priveleges: they can’t install or remove software, and are not part of the “games” group. The first restriction appears effective when I tested it, but the latter exclusion from the “games” group still meant they were able to play some games, for example those that originate from the python graphics libraries. My students, like teenagers everywhere, have at least a mild addiction to computer games, so I decided to remove them as a possible distraction. Since all students will use a single account, they will need their own USB thumb drive, since there won’t be many other ways to save files edited on the Raspberry Pi. However, since it has WiFi, there is always G-Drive or OneDrive.